Wire guide



March 20, 1956 K. A. SKARDAL 2,738,682

WIRE GUIDE Filed Nov. 25, 1953 2 Sheets-Sheet l March 20, 1956 A. SKARDAL WIRE GUIDE 2 Sheets-Sheet 2 50 &

Filed Nov. 23, 1953 United States Pa ifl Q I WIRE GU IDE Karl Arvid Skardal, Stockholm, Sweden Application November 23, 1953, Serial No. 393,860 Claims priority, application Sweden December 30, 1952 3 Claims. 01. 74-241 The present invention relates to a mechanism for controlling the position of an endless web, such as a wire, a felt or the like, hereinafter referred to as a wire, of a paper making machine, with a view to causing the wire to travel in a predeterminedposition on its supporting rolls. It-is already-known, in order to cause a wire wandering laterally on its supporting rolls to resume its proper position, to derive from thewandering wire an impulse only for initiating an adjusting movement, whereupon the adjustment proper is etfected by power derived from the driving mechanism of the wire supporting rolls or from the shaft of any of said rolls.

More particularly, the invention has reference to that type of wire guides in which the lateral adjustment of the wire in order to restore its proper position on the rolls after a wandering is effected by one of the bearings for the shaft of one of the wire supporting rolls, hereinafter referred to as the guide roll, in the longitudinal direction of the wire, so as to set the guide roll into a position to cause the wire to wander in the opposite direction as before. To this end the said shaft is journalled on one side of the wire in a bearing reciprocable in a direction parallel with the longitudinal direction of the wire and on the other side of the wire in a bearing mounted to swivel on a vertical pivot.

An object of the invention is to provide a wire guide operating on the above principle which is simple in construction and efficient in operation.

Another object of the invention is to provide a wire guide which acts positively to stop the wandering back of the wire as soon as its proper position is reached, thereby completely avoiding any tendency towards lateral oscillation of the Wire.

According to a feature of the invention the shaft of the guide roll is connected at its end engaging the reciprocable bearing, by means of a connecting rod or the like with a rotatably mounted cam the rotation of which is controlled by the lateral movement of the wire, the connection being such that a play corresponding to the length of stroke of the connecting rod exists in the engagement between the connecting rod and said cam. By virtue of said play a rotation of the cam of power derived from the wire may take place irrespective of the connecting rod, because the latter only in its dead centers is in such an engagement with the cam as to exert any resistance to the rotation thereof. By rotation of the cam the dead centers of the connecting rod and thus the position in the longitudinal direction of the wire of the bearing supporting the shaft end connected to the connecting rod may be varied.

In the accompanying drawing an embodiment of the invention is illustrated. Fig. 1 is a side elevation and Fig. 2 is a top plane view thereof. Fig. 3 is an end view looking from the right of Fig. 1, with certain parts removed, and Fig. 4 is a side elevation, partly in section, looking from the same side as in Fig. 1.

In the drawings, and particularly Figs. 1 and 2, the numeral 1 indicates a portion of the wire to be controlled,

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2 is the guide roll engaged thereby and 3 isthe shaft of the guide roll. Said shaft is journalled at its one end in a bearing, not shown, which is mounted to swivel about a vertical axis indicated at 4 in Fig. 2, while the opposite end of shaft 3 is journalled in a bearing 5 reciprocable in a path parallel with the longitudinal direction of thewire. To this end, in the example shown, said hearing 5 is slidably mounted in a guideway 6 bolted to a base plate 7. Bolted to said base plate is also a frame 8 for supporting the shaft 9 of a cam 10. The shaft 9 extends in a direction parallel with the longitudinal direction of the wire and is rigidly clamped to the frame 8, so-that it is held against rotation, the cam 10 being rotatably mounted on the shaft 9 by means of ball bearings 11,12, Fig.4. Provided onopposite sides of the cam 10' are packings 13,14, which areenclosed in hollow discs 15, 16 bolted tothe cam. One of said discs, in the example shown the one numbered 16, is shaped as a cog wheel. Meshing with said cog wheel is a rack 17 extending in a horizontal or approximately horizontal direction which rests loosely on the bog wheel. It is to be noted that the rack may, of course, occupy a more or less inclined position without departing from the scope of the invention. One end of the rack 17 is pivoted to an arm 18 rigidly connected to a link 19 connecting a stationary pin 20 on a bracket 21 bolted to the guideway 6 with a bolt 23 fastened to a beam 22 extending over the entire width of the wire 1. On the opposite side of the wire, the beam 22 carries a similar pin 23 connected by means of a link 24 to another stationary pin 20 so that the beam together with the links 19 and 24 constitute a parallel guide. The beam carries feeling members, preferably in the shape of blades 25 engaging the opposite edges of the wire.

The cam 10 is formed with a square thread 26. Said thread engages at its uppermost point a slot 27 formed in the lower edge of a connecting rod 28 controlled by a crank pin 29 on the end of shaft 3 projecting beyond the bearing 5. The slot 27 is a dimension in the longitudinal direction of the connecting rod, that is to say, in the axial direction of cam 10, which is larger than the dimension of the cam section in the same. direction by an amount corresponding to the length of stroke of the connecting rod in order to allow the movement of the connecting rod even while the cam is standing still. The position, in the axial direction of the cam, of the portion of the cam thread 26 in engagement with the connecting rod, however, determines the range of movement of the crank pin 29 and thus also the position of the respective end of shaft 3 and bearing 5 in the longitudinal direction of the wire.

In order to prevent the connecting rod from being unintenionally disengaged from the cam there is a guideway 30 provided at the cam shaft supporting frame 8, and in order to maintain the rack 17 in constant engagement with the cog wheel 16 an arm 31 is provided at frame 8, Fig. 4.

Since the operation may clearly appear from the foregoing description of the construction it is considered sufficient hereinbelow to only recapitulate it briefly.

As long as the cam stands still the angular position of shaft 3 is maintained unchanged, determined as it is by the angular position of the cam, since the connecting rod reciprocates between dead centers fixed by the cam. If the belt 1 moves laterally, as for instance, towards the observer in Fig. 2, the arm system 18, 19 is caused to swing in the direction of arrow a in Fig. 2 resulting in a displacement in the same direction of the connecting rod 17, see also Fig. 3. As a result, the cog wheel 16 is rotated counterclockwise in Fig. 3. This in its turn causes a corresponding rotation of cam 10 so that the point of engagement between the connecting rod 28 and the thread 26 is moved to the left in Fig. 2, with a resulting corresponding swinging movement of shaft 3. By virtue of the oblique positioning of the wire with relation to its prior position the wire is compelled to wander back to its normal position on its supporting rolls. This in its turn causes a simultaneous restoration of the previous position of the point of engagement between the connecting rod and the cam.

As far as mere constructional details are'concerned, variations may be made within the scope of the annexed claims.

I claim:

1. In a guide for the wire screen or felt of a paper making machine having a guide roll for said screen or belt, a shaft for said roll, a bearing reciprocable in a direction parallel with the direction of movement of the wire screen or felt for one end of said shaft, and a feeling device operable by a lateral wandering of the wire screen or felt on the guide roll out of a normal position thereof, the provision of a permanently closed power transmission between said feeling device and said shaft end, comprising in combination a rotatable shaft extending in a direction parallel with the direction of travel of the wire screen or felt, a cylindrical disc on said shaft, 21 thread-like cam on said disc, a crank pin on the movable end of the shaft of the guide roll, a connecting rod between said crank pin and said cam, a toothed wheel on the shaft of said disc, a rack in engagement with said toothed wheel and a lever connecting the feeling device to the rack for imparting a movement thereto under control of a lateral wandering of the wire screen or felt.

2. A wire guide as claimed in claim 1, and in which the slot in the connecting rod is a dimension in the longitudinal direction of said rod which is larger than the dimension of the thread in the same direction by an amount corresponding to the length of stroke of the connecting rod.

3. A wire guide as claimed in claim 1, characterized by the further feature that the feeling device comprises a link guide, including a pair of stationary pivots, another pair of movable pivots, a beam for interconnecting said movable pivots, and contact members on said beam for engaging opposite edges of the wire.

References Cited in the file of this patent UNlTED STATES PATENTS 262,332 Tozer Aug. 8, 1882 593,037 Weatherbee Nov. 2, 1897 1,126,267 McElwain Feb. 2, 1915 1,584,344 Aldrich May 11, 1926 

